The Carnivore’s Dilemma

Posted on June 25, 2009 by Courtney

Please welcome today’s guest poster, Chris. Chris is a lecturer at a university in Australia and blogs at A Free Man.

I am a committed carnivore, some might say a fanatical one, so this is going to be a difficult post for me to write. I’ve been thinking a lot about food lately and I’m slowly coming around to the conclusion that we’re doing not only ourselves a lot of harm with our gluttonous Western diets, but the planet as well.

I’m behind the curve on this one, as there has been a fair bit in the mainstream press and the chatterbox commentators about cow farts and global warming. As is typically the case with the TV ‘news’ personalities, a lot of this talk is the oversimplification peddled by ill informed idiots misunderstanding complex science. Let’s start fresh and leave this particular story aside. In fact, let’s leave climate change in general aside. I’m a geneticist, not a climatologist, and I don’t know enough about the topic to get into it in any real critical analysis.

But I think that we can probably all agree on some simple things. We can probably all agree that we need to be careful in terms of water use – particularly if you live in Australia, for example, or the Western United States. I think we can all probably agree that energy conservation is a good idea, that pesticide and fertilizer use should be minimized as should the amount of waste we generate as a species.

All on board? OK.

When I don’t know what is going on, when I can’t tease the facts away from the politics and ignorance – I put my scientist hat on and go to the primary scientific literature. In a recent issue of the American Journal of Clinical Nutrition I found a paper addressing the topic at hand – “Diet and the environment: does what you eat matter?“. A group at Loma Linda University (California), led by Harold Marlow, compared the environmental effects of vegetarian and non-vegetarian diets using a number of different parameters.

Their findings are not good news for the meat lovers among us.

The Loma Linda group first compared the diets of vegetarians and meat eaters and then gathered information about the production of these food items – what it takes to grow a grapefruit, for example. They used this information to calculate ‘use efficiencies’ for water consumption, energy used, pesticides applied and fertilizers applied. These use efficiencies allow us to estimate the environmental cost of producing fruit juice or beef for human consumption. Marlow’s group then made the comparison between the two diets by expressing these costs as a ratio of non-vegetarian to vegetarian effects. If the ratio was high, that means that the meat eater’s diet is more environmentally costly. If the ratio is low (less than 1) that the vegetarian diet is more environmentally costly.

In almost every case, the non-vegetarian diet was much more costly. A non-vegetarian diet requires thirteen times as much fertilizer as a vegetarian diet. Chemical fertilizers are made up largely of phosphate, potassium and nitrogen. The first two elements are currently derived from non-renewable resources and the latter requires a heavy input of petroleum. Beyond that, heavy use of chemical fertilizers has resulted in water contamination, air pollution and loss of biodiversity.

Similarly, meat eaters use three times as much water to generate their dinner. Water availability is becoming a major issue in many parts of the world and for me personally, this finding is the most disturbing. There are whole swaths of formerly arable land in Australia that have been rendered useless due to dry land salinity caused by irresponsible agricultural practices. Marlow’s group calculates that switching to a vegetarian diet would conserve the equivalent of 54% of an average household’s weekly indoor water consumption or about 1,000 litres of water a week.

Perhaps the most immediate source of concern, however, is primary energy input. This is the amount of total energy required to grow your food and get it to your dinner table. A non-vegetarian diet requires 2.5 times as much energy to produce as a vegetarian diet. Most of this energy comes from fossil fuels and in the U.S., fossil fuel consumption has doubled in the last 20 years while the caloric return per calorie of input on most crops has diminished – it is taking twice as much fuel to produce the same amount of food. Most cereals and legumes provide 2-3 nutrient calories per calorie of primary energy input – this is a good solid energy investment. Fruits and vegetables usually get around 0.5 calories of nutrient energy per calorie of primary energy input – these cost more in energy than what they return, but still a pretty good deal. Meat, however, returns 0.01 – 0.05 calories per calorie of input energy. In short, meat costs us a lot of energy to produce and doesn’t provide much in return.

There’s a tidbit of good news for those of you who, like me, love nothing more than a good steak on the barbie – there was only a negligible difference in pesticide use between the two diets. Small comfort.

This is not the first of these studies to be undertaken. In 2003, another study in the American Journal of Clinical Nutrition found that a non-vegetarian diet had twice the environmental impact of a vegetarian diet. There was an exhaustive study in The Lancet in 2007 that got the ball rolling regarding the connection between modern livestock practices and an increase in greenhouse gasses, finding that livestock production accounts for as much as one-fifth of total greenhouse gas emissions. What I like about the current study, however, is that it breaks things down into easily digestible morsels. It simply costs the planet more for me to eat meat.

So what to do about it? Marlow’s group talks about ending agricultural subsidies and installation of more efficient water fixtures and diverting funding to research. But change, despite what you may hear on the television, probably has to come from the ground up when it comes to the environment. The primary problem in environmental terms is beef. So, eating more poultry or fish would be a start. The authors of The Lancet study suggest that a meagre 10% reduction in the amount of meat that we consume would have a beneficial effect on the environment. My family has started eating at least one vegetarian dinner a week and if I can do it, I’m pretty sure that anyone can.


  1. Chris, this is such a great post! I do think that reduction is a great way to get closer to a solution and to be more inclusive in getting people to commit to changes. Moderation is often easier than just cutting something out of your diet completely.

    June 25th, 2009 at 1:35 pm
    Comment by Allie
  2. Yes, a fantastic post indeed. I also like the idea of moderation in our diets — it’s much easier to get people on board if they don’t have to make drastic changes.

    I’d be interested in hearing if there’s any major difference in terms of the environmental impact of eating grass-fed beef vs. cows that have been force fed corn and grain. I imagine the water usage would be about the same, but maybe the energy input would be less for grass-fed cows. I also wonder about an organic diet vs. non-organic. The pesticide measure would obviously go way down, but I’m curious about the energy and water usage of an organic diet.

    June 25th, 2009 at 2:54 pm
    Comment by courtney
  3. There are couple of things to consider. First, all of US agriculture from broccoli production to beef production produces 6.2% of US greenhouse emissions according to the EPA. All of livestock agriculture in the US accounts for less than 2.5 % of greenhouse gas emissions. More than half the agricultural land in the United States is unsuitable for crop production. Grazing animals on this land more than doubles the land area that can be used to produce food in this country. An Iowa State University study comparing conventional, grain-fed beef production with grass-only production showed conventional beef production decreases the amount of land required to produce a pound of beef by two- thirds. In addition, conventional beef production results in a 40% reduction in greenhouse gas emissions per pound of beef compared to grass-fed beef production. Raising cattle serves a valuable role in the ecosystem by converting the forages humans cannot consume into a nutrient-dense food. Often these studies that compare veg diets to non-veg diets make the assumption that cattle eat grain their entire life which is simply not true. The majority of their life is on forages, not grain. At the end of the day, you are correct, moderation in everything is the key.

    June 25th, 2009 at 3:55 pm
    Comment by Heather
  4. Just to clarify, Heather, we’re not talking about emissions here. I don’t even want to get into that debate. The reason for that is that everyone has a favorite statistic that they like to throw around, for example that beef production reduces greenhouse gas emissions. And a lot of these statistics are from questionable sources.

    That’s why I kept things simple and focused on issues about which there’s little debate. I’m a meat eater, so I’m not out to get the beef industry. The fact of the matter is that if you’re trying to live light on the land, eating a lot of beef is not a good idea. I don’t like this. I like beef. But these are the facts.

    Oh, and as for the assumption that cattle eat grain their entire life, the researchers in the study that I cited used data from federal, state and county agencies in addition to industry associations. So they got all the ‘facts’.

    June 25th, 2009 at 8:14 pm
    Comment by A Free Man
  5. Just to clarify, Heather, we’re not talking about emissions here. I don’t even want to get into that debate. The reason for that is that everyone has a favorite statistic that they like to throw around, for example that beef production reduces greenhouse gas emissions. And a lot of these statistics are from questionable sources.

    That’s why I kept things simple and focused on issues about which there’s little debate. I’m a meat eater, so I’m not out to get the beef industry. The fact of the matter is that if you’re trying to live light on the land, eating a lot of beef is not a good idea. I don’t like this. I like beef. But these are the facts.

    Oh, and as for the assumption that cattle eat grain their entire life, the researchers in the study that I cited used data from federal, state and county agencies in addition to industry associations. So they got all the ‘facts’.
    Sorry… forgot to say great post – can’t wait to read your next one!

    June 26th, 2009 at 4:48 am
    Comment by Comment on The Carnivore’s Dilemma by A Free Man
  6. Seems like I remember statistics that said it was much more than 3 times the amount of water used–perhaps it depends on where the meat was produced. Obviously areas of heavy rainfall require less water than desert areas. And a huge amount of water is used in the production alone, to clean the facilities.

    I do remember that you can take a shower for a year with the water it takes to produce one lb of beef.

    Despite all the press about the carbon emissions it takes to produce meat, I suspect it will be the water issue that finally strikes the nail in the coffin of the SAD diet.

    June 26th, 2009 at 4:55 am
    Comment by KathyF
  7. I don’t understand: what’s the dilemma?

    You’ve stated the facts, and drew the conclusions: eating meat is indeed very bad for the environment. You care for the environment. Therefore, you should stop eating meat. The fact that you continue to do so either means that you subscribe to what some science-minded folks call “woo”–OR the particular aspect of environmentalism that eating meat affects most (water and land use) are not important enough for you to forego the pleasure of a thick juicy steak more often.

    Poultry, FWIW, isn’t all that much better. And fish is hard to get right (farmed? how’s it caught? is it one of the stocks that will be completely gone in two years?).

    June 26th, 2009 at 8:50 am
    Comment by Jules
  8. Your conclusion is to eat less beef. Isn’t an alternate answer to this dilemma lie in optimizing production? Using renewable fuels to power production, feed that requires less water and fertilizer, and using sustainable farming practices would greatly reduce/eliminate this problem, right?

    June 26th, 2009 at 9:46 am
    Comment by Nathan B.
  9. Kathy – Statistics are a lot like opinions, if you know that old saying. That’s why I try to stick with published, peer-reviewed scientific literature. You know that at the very least, the data has been checked by a couple of other scientists.

    Jules – Let me see if I can put this diplomatically. Part of the problem that the Green movement has is that it is perceived as shrill, self-righteous and totalitarian. As long as that’s the case, it will never convince the majority of people to make changes. For example, when I read a blog comment painting things in shades of bold black and white, I want to say ‘Forget it. These people can’t be satisfied. Fire up the grill.” It’s naive to think that every person who is concerned about the environment is willing or able to take on every mandate. Baby steps. Baby steps.

    Nathan – Absolutely. But in my experience, things don’t change at that level. There’s always big talk, but unless producers are forced to change- which they won’t be because the government regulators move at a snail’s pace – they won’t change. As Courtney pointed out, buying organic beef or poultry is another good alternative, there are a lot of little things one can do and the more little things that one does, the better off we are.

    June 26th, 2009 at 6:12 pm
    Comment by A Free Man
  10. It might also be worth considering meats beyond cow for your red-meat meals, particularly if they are locally sourced; small farms haven’t the margin for a bunch of waste, so many of the smaller farmers are choosing animals suited for–and less harmful to–the region. And it’s no more expensive for me to buy local buffalo than organic beef; YMMV, or course.

    June 26th, 2009 at 6:42 pm
    Comment by DSF
  11. Have you heard of this movie:


    I’m waiting for it to come out over here (does look a bit sensationalistic, but oh well.)
    Nice article! I tend to believe what “they” say about all this read meat being really bad for us anyway (let alone the environmental impact). I love a good brat, cheeseburger, hotdog, carpaccio, etc, but I’m also concerned about consumptions levels on a personal level, the environmental impact, and also for the animals. (Not that I don’t think we should eat them, but that they should be farmed in a more humane way.)

    June 27th, 2009 at 9:16 am
    Comment by Danielle
  12. I am what is called a “flexatarian”. My husband and kids are vegetarian and I cook all veg at home but I still enjoy meat if it is served at family and friends and occasionally eat it out.

    You may have read them but I highly recommend two books, both by Michael Pollan. One is the Omnivore’s Dilemma and the other is In Defense of Food: An Eater’s Manifesto. His philosophy, which closely parallels the slow food movement, sustainable eating and buying local, has dramatically changed the way my family shops and eats.

    He doesn’t eschew meat but for health and environmental reasons, suggests that it be like a condiment with the other food. Feeding cattle cheap corn rather than grazing(which is how the majority of beef is now produced)has made meat far cheaper($ cost only) which in turn has increased consumption and with it health issues(in part because the cows themselves are not eating what they should be as ruminates). Ah, don’t get me started, my husband makes fun of me when I start rambling on about how corn is the devil but seriously, what the influx of US government subsidized corn production has done to our diets is abysmal.

    I am a giant foodie, love to cook, love to eat and I have found just a slight shift in how I shop and how I eat has made me more conscious of and conscientous about what I eat.

    June 28th, 2009 at 10:13 pm
    Comment by chris/formerlyfun
  13. Chris, I ordered ‘The Omnivore’s Dilemma’ last week!

    June 29th, 2009 at 7:58 am
    Comment by A Free Man
  14. I’m so glad, it’s really awesome and it’s not about being a food Nazi as much as nurturing a relationship between the people who produce food and eat food. I am a raving fan but if you like Omnivore’s Dilemma, the next book was very good also. I think meat can be a part of someone’s diet without them having to sweat the environmental costs. Michael Pollan’s website also features links and resources for eating responsibly.

    June 29th, 2009 at 5:00 pm
    Comment by chris/formerlyfun
  15. [...] I’ve become increasingly concerned about eating meat. With beef in particular there are serious environmental and health concerns that I’m struggling to square with my lust for red meat. With a wee one or two in the picture, I decided to cut back a bit – a couple of meatless meals a week. However, faced with these H cup chicken breasts I made the decision to go even further – three maybe four meatless dinners a week – and to actively seek out ‘organic’ meat when we did go carnivorous. [...]

    November 5th, 2009 at 1:40 am
    Pingback by Who mistook the steak for chicken? | A Free Man
  16. [...] you must make is whether or not to eat meat. Here at The Greenists, we’re aware that a vegetarian diet is much less taxing on the planet than an omnivorous one, and we know how much better it is to eat locally-grown food, but we do not judge others if they [...]

    January 14th, 2010 at 4:02 am
    Pingback by Could You Hunt Your Own Meat?
  17. [...] we don’t judge people for eating meat — but we can’t ignore the fact that a vegetarian diet is much less taxing on the planet than a carnivorous one. One of my friends recently saw this TED Talk video, and it inspired him to become a weekday [...]

    May 24th, 2010 at 4:01 am
    Pingback by TED Talk: Being a Weekday Vegetarian
  18. There’s a UN report titled ‘Livestock’s Long Shadow’. Google that title and you can download it. The conclusions run along the same lines as the original author but add some other powerful detail. There some other things to consider. For example, there are a large number of people on this plantet that are hungry every day. By some estimates this is as many as 1 billion humans. Beyond just being nice to the planet and improving your health, when you consume less meat you leave more food for others. We don’t like statements like that because it sounds pretty judgemental but that’s the net economic impact. If you consume less meat, less will be produced and more resources dedicated to producing those animals will be put into non-meat food production. The population of the earth is growing and we will eventually have to make some serious choices about resource allocation. I hope we make those choices with our eyes open and with our heads and hearts. We are one species. Good health and long life to you all.

    February 25th, 2011 at 4:08 pm
    Comment by Scott K
  19. [...] the enormous environmental impact of meat production, have someone slap you in the face and then read this post immediately.) It’s an easy way to get a meatless meal into the [...]

    September 8th, 2011 at 3:26 am
    Pingback by Every Burger Deserves an Open Mind (and Mouth)

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